Role of Neto1 extracellular domain in modulation of kainate receptors.
Int J Biol Macromol
; 192: 525-536, 2021 Dec 01.
Article
em En
| MEDLINE
| ID: mdl-34634333
ABSTRACT
Kainate receptors play fundamental roles in regulating synaptic transmission and plasticity in central nervous system and are regulated by their cognate auxiliary subunits Neuropilin and tolloid-like proteins 1 and 2 (Neto). While electrophysiology-based insights into functions of Neto proteins are known, biophysical and biochemical studies into Neto proteins have been largely missing till-date. Our biochemical, biophysical, and functional characterization of the purified extracellular domain (ECD) of Neto1 shows that Neto1-ECD exists as monomers in solution and has a micromolar affinity for GluK2 receptors in apo state or closed state. Remarkably, the affinity was ~2.8 fold lower for receptors trapped in the desensitized state, highlighting the conformation-dependent interaction of Neto proteins with kainate receptors. SAXS analysis of Neto1-ECD reveals that their dimensions are long enough to span the entire extracellular domain of kainate receptors. The shape and conformation of Neto1-ECD seems to be altered by calcium ions pointing towards its possible role in modulating Neto1 functions. Functional assays using GluK2 receptors and GluK2/GluA2 chimeric receptors reveal a differential role of Neto1 domains in modulating receptor functions. Although the desensitization rate was not affected by the Neto1-ECD, the recovery rates from the desensitized state are altered.
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Base de dados:
MEDLINE
Assunto principal:
Receptores de Ácido Caínico
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Domínios e Motivos de Interação entre Proteínas
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Proteínas do Tecido Nervoso
Idioma:
En
Ano de publicação:
2021
Tipo de documento:
Article